78191055 has 32 divisors (see below), whose sum is σ = 139773120. Its totient is φ = 41472000.

The previous prime is 78191051. The next prime is 78191089. The reversal of 78191055 is 55019187.

It is not a de Polignac number, because 78191055 - 2² = 78191051 is a prime.

It is a super-2 number, since 2×78191055² = 12227682164026050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78191051) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 24555 + ... + 27555.

It is an arithmetic number, because the mean of its divisors is an integer number (4367910).

Almost surely, 2^78191055 is an apocalyptic number.

78191055 is a deficient number, since it is larger than the sum of its proper divisors (61582065).

78191055 is a wasteful number, since it uses less digits than its factorization.

78191055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3208 (or 3202 counting only the distinct ones).

The product of its (nonzero) digits is 12600, while the sum is 36.

The square root of 78191055 is about 8842.5706104051. The cubic root of 78191055 is about 427.6144353542.

The spelling of 78191055 in words is "seventy-eight million, one hundred ninety-one thousand, fifty-five".